Alondra Nelson has followed how African-Americans are using DNA tests to help answer questions about their identities that were lost during the transatlantic slave trade. Her book, "The Social Life of DNA: Race, Reparations and Reconciliation After the Genome," chronicles their experiences. She joined Hari Sreenivasan to discuss.Video Caption ...

HARI SREENIVASAN, PBS NEWSHOUR WEEKEND ANCHOR: In the past decade, companies such as 23andMe, Ancestry.com, which provides genetic testing to help people learn more about their DNA have boomed. These tests offer insights about diseases, diet and inherited health related traits ...